Jean Pierre Vartanian

..Thus, even nonmutagenized FMDV quasispecies include a deep, mutationally biased portion of sequence space, in support of the view that the virus replicates close to the error threshold for maintenance of genetic information...

..Although the mutant spectrum resulting from A3 editing is highly deleterious, a very small part, notably the lightly edited genomes, might help the virus evolve and even escape immune responses...

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..This qualitative and quantitative variation among primate A3A genes suggest that subtle differences in function might ensue as more light is shed on this increasingly important enzyme...

..TRIB3 has been linked to cancer and via its own interactors and links the A3A DNA mutators to the Rb-BRCA1-ATM network. TRIB3 emerges as an important guardian of genome integrity...

..That the A3C gene is not induced by type I interferons begs the question whether some herpesviruses encode A3C antagonists...

..This death mechanism is circumvented by the HIV viral infectivity factor protein, which prevents APOBEC3G from entering the virion...

..Nonetheless, hyper- and lightly mutated sequences went hand in hand, raising the hypothesis that recurrent low-level mutation by APOBEC3A could catalyze the transition from a healthy to a cancer genome...

..APOBEC3G deamination of dC or dCTP was not detected. In short, APOBEC3G is a single-stranded DNA cytidine deaminase capable of restricting retroviral replication...

..The degree of hypermutation varied smoothly among genomes indicating that the number of APOBEC3 molecules packaged varied considerably...

..There seems to be more genetic editing in liver or cell-associated genomes than serum or culture supernatants, suggesting that too much editing of virion cDNA might impede completion of DNA synthesis...

..Analysis of sequences derived from the serum of two chronic carriers, indicated that hA1 explained only a small fraction of edited HBV genomes. By contrast, several human APOBEC3 deaminases were active including hA3G...

..An entire hepatitis B virus (HBV) genome was amplified and sequenced from samples taken from one animal. This indicates that HBV is distributed across the entire range of chimpanzee habitats...

..The hyperedited mutant frequency, including genomes and antigenomes, was a log greater for influenza virus compared to measles virus, suggesting a greater sensitivity to restriction by ADAR-1...

..In short, murine APOBEC1 is a hypermutator of both RNA and ssDNA in vivo, which could exert occasional side effects upon overexpression...

..These results show that HIV/SIV replication requires only a minimal set of cis-acting elements in the promoter and suggest a hitherto unrecognised requirement of flexibility for the nascent TAR structure to allow anti-termination by Tat...

..A phylogenic analysis of A3 exons revealed that A3G is in fact a chimera with the first two exons being derived from the A3F gene. This might allow co-expression of the two genes that are able to restrict HIV-1Deltavif efficiently...

..Thus, stochastic or transient overexpression of APOBEC3 genes may expose the genome to a broad spectrum of mutations that could influence the development of tumors...

..The editing of Alu elements in cellular mRNAs was strongly enhanced by type I interferon induction indicating a novel link mRNA metabolism and innate immunity...

..In infected hosts, the persistence strategy employed by FV might be based on low levels of replication, as well as avoidance of cells expressing large amounts of active cytidine deaminases...

..Hence, lineages are younger than anticipated previously, although not in proportion to the ratio of the intrinsic recombination/point mutation rate. Recombination also inflates codon polymorphisms...

..The data indicate that the HIST2H4 amplimers are, thus, suitable for both DNA quality testing as well as species identification in the animal kingdom...

..In conclusion, the present observations demonstrate that ADAR-1 massively edits HTLV-2 and STLV-3 retroviruses in vitro, but probably remains a rare phenomenon in vivo...

..For the APOBEC3 genes, not only is their physiological function unknown, but also their role in the induction of cancer remains to be determined. Yet given the pace of research, all this is certain to change in the next few years...

..Due to the lack of proofreading, these gypsy elements represent hypervariable loci within the Drosophila genome, suggesting that dNTP pool imbalances in vivo are mutagenic...